net: dsa: rename tagging protocol driver modalias

It's autumn cleanup time, and today's target are modaliases.

Michael says that for users of modinfo, "dsa_tag-20" is not the most
suggestive name, and recommends a change to "dsa_tag-id-20".

Andrew points out that other modaliases have a prefix delimited by
colons, so he recommends "dsa_tag:20" instead of "dsa_tag-20".

To satisfy both proposals, Florian recommends "dsa_tag:id-20".

The modaliases are not stable ABI, and the essential information
(protocol ID) is still conveyed in the new string, which
request_module() must be adapted to form.

Link: 20221027210830.3577793-1-vladimir.oltean@nxp.com
Suggested-by: Andrew Lunn <andrew@lunn.ch>
Suggested-by: Michael Walle <michael@walle.cc>
Suggested-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Tested-by: Michael Walle <michael@walle.cc>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net/dsa/dsa.c

@@ -108,7 +108,7 @@ const struct dsa_device_ops *dsa_tag_driver_get(int tag_protocol)
 	const struct dsa_device_ops *ops;
 	bool found = false;
 
-	request_module("%s%d", DSA_TAG_DRIVER_ALIAS, tag_protocol);
+	request_module("%sid-%d", DSA_TAG_DRIVER_ALIAS, tag_protocol);
 
 	mutex_lock(&dsa_tag_drivers_lock);
 	list_for_each_entry(dsa_tag_driver, &dsa_tag_drivers_list, list) {

net/dsa/dsa_priv.h

@@ -17,9 +17,10 @@
 
 #define DSA_MAX_NUM_OFFLOADING_BRIDGES		BITS_PER_LONG
 
-#define DSA_TAG_DRIVER_ALIAS "dsa_tag-"
-#define MODULE_ALIAS_DSA_TAG_DRIVER(__proto)				\
-	MODULE_ALIAS(DSA_TAG_DRIVER_ALIAS __stringify(__proto##_VALUE))
+#define DSA_TAG_DRIVER_ALIAS "dsa_tag:"
+#define MODULE_ALIAS_DSA_TAG_DRIVER(__proto) \
+	MODULE_ALIAS(DSA_TAG_DRIVER_ALIAS "id-" \
+		     __stringify(__proto##_VALUE))
 
 struct dsa_tag_driver {
 	const struct dsa_device_ops *ops;